Spark-plug for explosion-engines.



PATENTED MAY `5, i903c y l E. A. LA HAR. SPARK PLUG .PQR EXPLGSmrvfmwge.

Ammcwmf FILED Ami 3a, me?.

the shoulder or seat of e conoidal form.

UNITED ELLSWORTH A. LA HAR, OF FORESTVILLE, CONNECTICUT, ASSIGNOR TO JOHN B.

' NEWBRITAIN, CONNECTICUT.

man

nageur OFFICE. l

Specification. of letters Patent.

rammed May 5, 1908,.

Applicationle'd August 365, i90?. Serial No. 390,844,

To all tollem 'it may concern.' Ileit known thatl, ELLSWORTH A. LA Hna, acitizen of the United States, residing et Forestville, in 'the county of Hartford and` State of Connecticut, ,have yinvented cert'ein new and useful lrn noveinents in Sierlr v Plugs for Explosivelngines,y of whicthe ...following is e specification.

l Mv invention relates to iinprot/feinentsy in sparlrplug's for explosive engines und theobjects of 'my improvement are simplicity and economy in construction with convenience and efficiency in use.

In the accompanying drawing` 1-li igurel is a sectional elevation of my plug, the plenefolw section being longitudinal and central. Fig'. 2 is a side elevation of the holdingl socket end its tubular cap.. lig. 3 is a side elevation ol the spark rod and attached nuts and washers as removed` from the insulator. Fig'. 4 is side eleve-tionr ofA the insulator' and connected metallic sleeve by means of which sleeve the insulator-is held Within the socket, the said insulator being removed from the socket.

A desiffnates a socket or shell heving a connecter; electrode 5, an externally threaded. nec r6, an singular portion? for the applicew tion ol a Wrench, an internal shoulder or seat 8 of e conoidal forni and an internally screw threaded inouth 9. B, designates a tubular ce having an exterior thread l0 and angu ar portion ll, the bore of the said csp being substantially the same es4 the smaller bore of the socket A; These parte vare of an ordinary' construction excepting that I Ineke The socket is screwed into the engine in the ordinary way.

. I form my insulator, Whether of one orl many pieces, complete in itself with all the partsintact, and permanently connect it with a surrounding metallic sleeve or bushing so that the complete insulator may be held in place by holdingv the seidv sleeve or bushing Within the socket between'the shoulder 8 and the inner end of the tubular cap B. In the l particular form shown the lower end l2 of the the sleeve meldde' the sleeve at that point of' sleeve 13 is undercut or concevely beveled tolit the internal and conoidal seat 8 of the socket A, as shown in Fig. 1 and as indicated by broken lines in Fig. 4. I referto forni en inner rim' 14 neeriflthe longitudinal middle of a smaller internati diameter than at its ends. I build up the 'insulator assllown 1n Figs. l

end 4, ony a. body tube l5 that is threaded at each end for the reception of nuts I6 and 17. The body of the insulator, that is the insulating material, is' shown as composed of a lower porcelain tube 18, mica disks 19, and a porcelain tube 20. The rnica disks are of two sizes to lit the two dill'erent inner diameters of the sleeve.. The porcelain tubes are of about the same diameter and are small enough to be received Within the socket and tubular cap 'without crowding, because the insulator is held by the sleeve inst-eed ol by its lit to the socket, and consequently it is not necessary to have the insulating material come in con tout with the socket A or its tubular cap B. The holes in the mica disks and the inner bore of the porcelain tubes are such as to reecive the body 'tube l5 end substantially lit 'the seine. After properly placing; the tubes, disks and metallic sleeve on the body tube, they ure ell lirrnly secured together in e single structure by screwing u one of the nuts on the ends of the body tu e. The mica disks permit of a sufficient yielding so that the porcelain tubes are not broken by screwing un 'the nut.

The spark rod 2l vis substantiallybf an or dinaryconstruction, having ashoulder 22 at its lower end while its body is of a to be Lli'eceived within the body tube end its u ppcr end 23 is threaded. The usual nut 24e for holding the ,rod in 'the insulator, end `the uut or washer 25 and nut 26 for binding' a conduct-ing Wire areapplied to the said threaded end. The general operation ol! the plug is the same as that of'snnilar plugs now in use. By inyinvention, I provide a detachable insulator that is complete in itself indeI endently of the spark rod so that the spar i rod can be readily removed for cleaning or reairs or for substituting a new rod while the insulator is intact. By the employment ol" s rnetel sleeve ernianently connected with this insulator, tile complete insulator maybe held in the socketv through the said sleeve, instead of through the more fragile insulating material that is liable to crumble or breelr.-

this sleeve, especially when tltt, l"J 4 a beveled seat, a 'gas tight jointis 'term lso thet there is no lcelrsge olgas through the eoclretrrorn the engine. the employnientofn body tube rnetel s "n enabled to use mica dislrs for elasticity ninfthe sleeve end inoresulnltent ,but less elestic porcelain outs-ide ell the lt is apparent that some changes from the specific construction herein disclosed may be made and therefore l do not wish to be 1in-- derstood as limiting myself to the precise form of construction. shown and deseribed, but desire the liberty to make suoli changes, in working my invention, as may fairly come within the spirit and scope oi the same.

Ivcleim as inv invention:

l. A spark plug comprising 'a .holding socket, having an internal seat, a. tubular ca for said socket, an insulator com lete in itse l' and a middle slee-Ve ermanent y connected with the said comp ete insulator, the. said' sleeve. being fitted within the said socket and to the said seat therein. for holding the insulator in the socket through the said sleeve.

2. A spark. plug comprising a holding socket having' an internal seat of a conical fo1m,'a tubular cap for said socket, an in sulator complete in itself, and a middle sleeve within which the said insulator is' mounted, the lower end of the said sleeve being under cut to lit the cciioidai seat of the `said socket.

seams centr'al tube bv mea-ns of .which the said sleeve and insulating body7 are held together one complete and detachable insulator. s 4. A spark plug comprising an insulator consisting of an insulating body formed of difiere-nt pieces, a middle metallic sleeve surrounding the middle portion of the .said insulating body, and a central vbody tube connectinff :is one part the several parts of the complete insulator. V

` 5. AI spark plug comprising an. insulator consisting of Yan insulatii'ig body; portion composed of mica and olcelain, a middle metallic sleeve suir anfing the middle portion. of the said insulating body, a central body tube having a threaded end and a nut forr binding the several parts one on the `said bodyv tube.

GQ A spark plug comprising ali-insulating body ortiou, a middle sleeve siu'rouiiding the said insulating body portion, a central body tube by means of which the said insulating bodwT and sleeve are held together, and a se arately formed detachable spark rod 'litten Within the said tube.

E LLSWORTH A. LA HAR. Witnesses: y,

i Smimr E. STGCKWELL,

JOHN B. SMITH. 

